The objective of this proposal is to describe the anatomical distribution of luteinizing hormone releasing hormone (LHRH) and other neuropeptides in the central nervous system of the mouse, rat, guinea pig and rabbit and, with the development of procedures which optimize their localization, to foreward the technique of immunocytochemistry to quantitative analysis of neurohormone content. Assessment of neuropeptide content will be made following experimental neuroanatomical manipulations and during various neuroendocrine states.